PERSISTENT SPECTRAL HOLE-BURNING OF EU3-GLASSES( IONS IN SILICATE)

Measurements of spectral hole burning have been carried out for glasse s with compositions of (75 - x)SiO2. xAlO(3/2). 25NaO(1/2). 1.0EuO(3/2 ) (x = 0, 10, 15, 20, 25, 35) at 4.2 K. A persistent spectral hole can only be burned in silicate glass containing Al2O3 The hole burning is accompanied with no antiholes and lasts for 30 min to Ih. This phenom enon is in contrast to the hole shape and lifetime observed in an opti cal pumping mechanism due to Population redistribution among the hyper fine levels previously reported for Eu3+-doped silicate glass. With an increase in Al2O3 content, the hole linewidth becomes narrower and th e hole depth increases. The variation in the hole linewidth can be exp lained in terms of the structural, changes in the aluminosilicate glas s.